LONDON, April 30, 2026 (GLOBE NEWSWIRE) -- A provocative campaign has launched on the London Underground by Project Slingshot, aiming to bring to light the secretive practice of slaughtering pigs in gas chambers.
Supported by comedians Diane Morgan, Jen Brister and Shabaz Ali, TV’s Dr Amir Khan, and TV personality and athlete Mathew Pritchard, the ads challenge the industry’s claims that CO2 gassing qualifies as “humane slaughter”. Each high-profile supporter dismisses the claim in their own words and lands with the same conclusion: “I don’t buy it.” Diane Morgan says: “I looked up humane in the dictionary and I have to say gassing didn't come up.”
Other well-known supporters of the campaign include comedian Simon Amstell, author and historian Rutger Bregman, actor Sir Mark Rylance (quote below), Meat Free Monday founders Paul, Mary and Stella McCartney (quote below) and Neil Duncan-Jordan MP, who says: “We've been told for decades that CO2 gas chambers are humane. The pigs screaming inside them tell a different story. I don't buy it. The public doesn't buy it. Westminster shouldn't either. Ban them."
In England and Wales, 90% of pigs are slaughtered inside CO2 gas chambers, which according to a 2025 report by a government advisory body, causes severe pain, fear, anxiety, and respiratory distress. The government’s December 2025 animal welfare strategy announced a phase-out of CO₂ gassing for pigs, but Project Slingshot, the group behind the campaign, believes the commitment is little more than hot air. They have accused the government of capitulating to an industry driven by profits, not welfare.
Says Project Slingshot’s co-founder, Naomi Hallum: “Despite the evidence that pigs experience severe pain and distress, and die gasping for air, the industry asks us to believe that they kill pigs in gas chambers, not because it is cheap, but because it is humane. We simply don’t buy it. This has all the hallmarks of industrial-scale gaslighting. It seems that while the pigs get gassed, the rest of us get gaslit.”
Says actor Sir Mark Rylance: “We're killing nine out of ten pigs in gas chambers. The government knows it causes pain and fear. The industry knows we'd object if we knew. So they made sure we didn't.”
While the practice of slaughtering pigs inside gas chambers is indeed little known, when people do find out, the majority opposes it. In a survey commissioned by Project Slingshot, 81% of Brits said they found the practice unacceptable.
Project Slingshot’s co-founder Matthew Glover says: “The powerful agribusinesses behind the UK pig industry know the secret formula: make a killing by spending less on killing. We know that ending the CO2 gassing of pigs is a David-and-Goliath fight. They have the power. They sit on government boards. But we have the truth, and if they don’t like what we are saying, our lawyers are ready.”
Project Slingshot's goal is to ensure gas chambers – and all the other unacceptable practices and outcomes associated with industrial factory farming – are brought into the light, and ultimately to end factory farming by 2040. The group is supported by Meat Free Monday Founders, Paul, Mary, and Stella McCartney, who say: “Project Slingshot is doing exactly what needs to be done: pulling back the curtain on factory farming so that people can make informed choices. That moment of awareness is what changes minds.”
More than 750 ads will appear in 206 London Underground stations, and there are 2,200 more inside tube carriages, for two months. The stations include Euston, Charing Cross, Liverpool Street, Embankment, and Kings Cross St Pancras.
- Images of the posters, pigs inside gas chambers, and Project Slingshot assets can be downloaded here.
- Project Slingshot’s launch video featuring Diane Morgan, Dr Amir Khan, Jen Brister, Mathew Pritchard and Shabaz Ali can be viewed here.
- For more information or to arrange an interview, contact press@projectslingshot.com
About Gas Chambers for Slaughtering Pigs in the UK
In 2003, the government’s own advisory body recommended an end to CO2 gas chambers for pigs on the grounds that they cause unacceptable levels of pain and suffering. Since then, there has been no government action to curb it. Today, 90% of pigs in England and Wales are slaughtered in gas chambers. As Diane Morgan says: “This is not one bad apple. It’s the whole f***ing orchard.”
In 2021, an activist obtained undercover footage from inside a UK slaughterhouse using gas to kill pigs. It showed distressed pigs gasping for air.
In October 2025, the government’s Animal Welfare Committee released a full report on the impacts, which stated: “exposure of conscious pigs to high concentrations of CO2 is associated with three major welfare concerns: pain, respiratory distress and fear. These manifest behaviourally as vocalisations, hyperventilation and escape attempts.” In other words, screaming, gasping for air and trying in vain to flee.
In its December 2025 animal welfare strategy, the government announced that it would ‘phase out’ the use of CO2 for pigs. Since then, the industry has worked to defend its use of gas chambers, including commissioning a report that highlights the cost of adopting less aversive systems.
About Project Slingshot
Project Slingshot is a narrative pressure engine designed to operate the way that anti-tobacco campaigns and anti-drink-driving campaigns operated before it: by making it socially, politically and culturally impossible to keep defending reckless, dangerous industries and practices. Project Slingshot has factory farming in its sights. This is an industry that negatively impacts public health, communities, biodiversity, and animals while polluting rivers and air. Project Slingshot exists to bring these issues to light through a constant, high-visibility programme of truth-telling that is timed, sequenced, and designed to accumulate rather than fade. The suffering caused by CO2 chambers is the first of the group’s “drumbeats”.
A photo accompanying this announcement is available at https://www.globenewswire.com/NewsRoom/AttachmentNg/62d2d91d-4beb-49e0-bc2c-fac9c34d2086
